1. Field of the Invention
The present invention relates to a multicast method and apparatus applicable to a communication apparatus such as telephone and facsimile with the multicast communication function and the redial function.
2. Description of the Related Art
In some of facsimile, telephone numbers of communication partners can be assigned and registered for a one touch button and a short number function. In a facsimile with the multicast communication function, a plurality of destinations of communication partners for the multicast communication are assigned for a one touch button or the short number function, and the number of destinations capable of being registered at the same time for a one touch button or the short number function reaches tens up to hundreds. And in a facsimile apparatus with the multicast communication function, a plurality of jobs for the multicast communication can be registered. Some of such apparatus have the sequential transmission function in which one multicast communication starts while another one is hold for redial.
The communication procedure, in the case where a plurality of jobs for multicast communication are registered in a facsimile, is explained. FIG. 1A illustrates the case where the multicast communication (Job A) for multicasting paper document A to reception terminals D(1) and D(2), and the multicast communication (Job B) for multicasting paper document B to reception terminals D(2) and D(3) are registered, and reception terminal D(2) is in a busy condition.
In Job A, a redial interval occurs in the middle of Job A because reception terminal D(2) is busy and not available for the line connection. In Job B started during the redial interval, a call is performed to reception terminal D(2) registered at the head of Job B. In the case where reception terminal D(2) is still busy, a call is changed to terminal D(3) of the next order because the line connection is not established as well as Job A. When a call is performed to reception terminal D(3) and the line connection is established, paper document B is transmitted. When the calls to all reception terminals registered in Job B are finished, if reception terminal D(2) to which the transmission is not completed because of busy condition is left, Job B is on hold to redial to it.
In Job A, after the redial interval passes, a call is performed again to reception terminal D(2) to which a transmission is not performed. In the example illustrated in FIG. 1A, the busy condition of reception terminal D(2) is dissolved during the redial interval, the transmission is completed and the job is finished. In Job B, after the redial interval passes, a call is performed to reception terminal D(2) to which the transmission is not performed and paper document B is transmitted.
FIG. 3A illustrates the case where two jobs are registered, where one is the multicast communication (Job A) for multicasting paper document A to reception terminals D(1) and D(2) by password transmission and another one is the multicast communication (Job B) for multicasting paper document B to reception terminals D(3) and D(4) by password transmission, reception terminal D(1) is in a busy condition, reception terminal D(2) is in an error condition caused by a line termination and reception terminal D(3) is in an improper password condition.
In job A, a communication error is caused in the middle of the communication to reception terminal D(2) by a line termination, a call is performed to reception terminal D(2) again immediately, and a transmission is performed. The redial interval is set for reception terminal D(1) to which a communication is not performed because of busy condition.
On the other hand, Job B is started when a condition of Job A changes to the redial interval. In Job B, a password is transmitted to reception terminal D(3) and a communication error occurs because the password is improper. A call is repeated to reception terminal D(3) in a communication error, and a call destination is changed to the next one; reception terminal D(4) after a certain number of continuously communication errors occur.
In the facsimile apparatus described above, the case occurs where, while one user is performing a multicast communication in which a plurality of destinations are registered, another user may register another multicast communication. In this case, the same destination as that registered in the multicast communication already performed may be overlapped and selected as a destination (D(2)) for the multicast communication registered later. When a line connection is not established to destination (D(2)) because of busy condition and a redial interval for that is set by the first job, if a call is performed to destination (D(2)) by another multicast communication job registered later, it is obvious that the communication is not established and the job enters the redial interval. As a result, at least two redial interval occurs until two multicast communications finish, which means it takes a long time to finish transmissions.
And in the facsimile apparatus described above, when a communication error occurs, a call is performed repeatedly so that the transmission is completed. However in the case where a communication error is caused by an improper password for a destination, it is impossible to establish a communication to the same destination by calling repeatedly a numbers of times. Because of it, it takes a time to move to the next destination, which requires a long time to finish the multicast communication for all destinations.
In a manner described above, in a communication apparatus represented by a facsimile apparatus with the multicast communication function and the redial function, since a call is performed repeatedly to a destination to which a connection or a communication is impossible until one multicast communication is finished to all destinations, that may allow unnecessary high occupation rate of line.
The present invention is carried out based on the facts described above and has the object to provide a multicast method and apparatus capable of saving a duration time consumed to finish a multicast communication for all destinations and preventing the occupation of line by the multicast communication, by calling primarily to a destination to which a connection or a communication is possible.
In a simultaneous multicast method in the present invention, a destination to which a line connection fails in the process of simultaneous multicast to a plurality of destinations is memorized, and when the memorized destination is included in another multicast communication stared later, a call to the destination is skipped and a call to another destination is primarily performed.
According to the present invention, in the case where a destination to which a line connection fails in the former multicast communication is included in the later multicast communication, a call to such destination is skipped. For instance, in the case where the connection is not established by busy condition, a call can be performed after the possibility of busy condition lowers, which permits to finish a job in a shorter time.
And in a simultaneous multicast method of the present invention, when a communication error occurs in the process of simultaneous multicasting to a plurality of destinations, in the case where a communication error to a destination is caused by the reason proper to call again, a call is repeated to the same destination, and in the case where a communication error to a destination is caused by the reason improper to call again, a call to the same destination is prevented. That is to say, a call is performed again to a recommunicatable destination, and a call is not performed again to an inrecommunicatable destination.
According to the present invention, in the case where a communication error to a destination is caused by the reason improper to call again, a call to the same destination is not performed without useless calls. For instance in the case where a communication error is caused by an improper password, useless calls to the same destination are omitted. That results in reducing the time consumed to finish all of a plurality of multicast communications.
And the present invention provides a multicast communication apparatus comprising a multicast function to simultaneous multicast to a plurality of destinations, a redial function to set the redial interval for a destination to which a connection is not established, a memory in which error information of the destination to which a connection is not established is memorized, a delete function to delete the error information of the destination to which a connection is not established once then completed in the memory, a sequence function to start a plurality of multicast communications sequentially during the redial interval, and a function to control the call order to skip the destination which error information is registered in the memory.
And the present invention provides a communication apparatus comprising a multicast function to simultaneous multicast to a plurality of destinations, a redial function to set the redial interval for a destination to which a connection is not established, a sequence function to start a plurality of multicast communications sequentially during the redial interval, a memory in which the error type of the occurred communication error is memorized and a function to control not to call again the destination which error type is memorized as an inrecommunicatable one in the memory.
And the present invention provides a communication apparatus for multicast communicating comprising a function to simultaneous multicast the same paper document to a plurality of destinations, a function to set a redial interval for a destination to which a connection is not established for each paper document, a control section to control a call order, when a plurality of simultaneous multicasts are performed, in the case where a destination set a redial interval in a simultaneous multicast is included in destinations in another simultaneous multicast, to skip the destination in another simultaneous multicast.
And the present invention provides a communication apparatus for multicast communicating comprising a function to simultaneous multicast the same paper document to a plurality of destinations, a function to memorize an error information concerning a destination to which a connection is not established for each paper document, and a control section not to call to a destination which error type is memorized as an inrecommunicatable one in a simultaneous multicast and to shift to another simultaneous multicast processing when a plurality of simultaneous multicasts are performed.